We report on a 116 Gb/s on-off keying (OOK), four pulse amplitude modulation (PAM) and 105-Gb/s 8-PAM optical transmitter using an InP-based integrated and packaged externally modulated laser for high-speed optical interconnects with up to 30 dB static extinction ratio and over 100-GHz 3-dB bandwidth with 2 dB ripple. In addition, we study the tradeoff between power penalty and equalizer length to foresee transmission distances with standard single mode fiber.

We experimentally demonstrate a DMT transmission system with 1.55-μm EML using nonlinearity-aware time domain super-Nyquist image induced aliasing. Compared with linear equalization, the capacity is improved by ∼16.8%(33.1%) with proposed method for 4(40) km transmission.

We experimentally demonstrate a DMT transmission system with 1.55-mu m EML using nonlinearity-aware time domain super-Nyquist image induced aliasing. Compared with linear equalization, the capacity is improved by similar to 16.8%(33.1%) with proposed method for 4(40) km transmission.

A differential pulse code modulation (DPCM) based digital mobile fronthaul architecture is proposed and experimentally demonstrated. By using a linear predictor in the DPCM encoding process, the quantization noise can be effectively suppressed and a prediction gain of 7 similar to 8 dB can be obtained. Experimental validation is carried out with a 20 km 15-Gbaud/lambda 4-level pulse amplitude modulation (PAM4) intensity modulation and direct detection system. The results verify the feasibility of supporting 163, 122, 98, 81 20-MHz 4, 16, 64, 256 QAM based antenna-carrier (AxC) containers with only 3, 4, 5, 6 quantization bits at a sampling rate of 30.72MSa/s in LTE-A environment. Further increasing the number of quantization bits to 8 and 9, 1024 quadrature amplitude modulation (1024 QAM) and 4096 QAM transmission can be realized with error vector magnitude (EVM) lower than 1% and 0.5%, respectively. The supported number of AxCs in the proposed DPCM-based fronthaul is increased and the EVM is greatly reduced compared to the common public radio interface (CPRI) based fronthaul that uses pulse code modulation. Besides, the DPCM-based fronthaul is also experimentally demonstrated to support universal filtered multicarrier signal that is one candidate waveform for the 5th generation mobile systems.

We propose a low complexity timing algorithm for high order PAM. Experimental results demonstrate higher performance and lower complexity than conventional algorithms in a 32 Gbaud PAM-8 transmission over 4 kin SMF links.

Electrical duobinary modulation is considered as a promising way to realize high capacity because of the low bandwidth requirement on the optical/electrical components and high tolerance toward chromatic dispersion. In this paper, we demonstrate a 100 Gb/s electrical duobinary transmission over 2 km standard single-mode fiber reaching a bit error rate under 7% HD-FEC threshold with the use of PRBS7. This link is tested in real-time without any form of digital signal processing. In-house developed SiGe BiCMOS transmitter and receiver ICs are used to drive an electroabsorption modulated laser and decode the received signal from a PIN-photodiode. The performance of 50 and 70 Gb/s nonreturn-to-zero and electrical duobinary transmission are investigated for comparison.

This paper describes improved results when comparing cascaded traveling wave electro absorption modulator (TWEAM) to non-cascaded TWEAM by simulation. Large signal modeling is used for both types of modulators to achieve 4 and 10 dB extinction ratios (ERs) with flat frequency response for applications in short distance as well as long distance optical fiber communication. To obtain 4 and 10 dB ERs with 110 GHz 3 dB bandwidth, a cascaded TWEAM requires 0.4V peak to peak (Vp-p) and 1 Vp-p input driving voltages respectively. A non-cascaded TWEAM requires about two times the input driving voltage compared to the cascaded modulator to achieve the same values of ER and 3 dB bandwidth. Both modulators have been simulated with the same bias and also use the same circuit parameters except for the total active segment lengths (1 and 0.5 mm for cascaded and non-cascaded modulator respectively) and microstrip lengths to obtain the same ERs and 3 dB bandwidths.

Error free transmission (E-12) over 55 m long standard MMF at 40 Gb/s data rate is demonstrated with moderate signal conditioning on the VCSEL. The VCSEL has a-3 dBe bandwidth of 15 GHz resulting in system bandwidth of 12GHz, giving 3.3 bit/s/Hz coding efficiency.

In 2010, the standard for 100GbE was approved, which specifies the transmission of 100 Gb/s via 4 wavelength channels of 25 Gb/s each. A solution based on a 100 Gb/s single wavelength channel is capable of significant cost reductions should the required components be available. Within the HECTO project, we developed components suitable for single-wavelength 100 Gb/s transmission. In this article, the project is described - its organization, objectives, possible impacts, and results - including the successful demonstration in a final field trial. A complete ETDM system utilizing the monolithically integrated transmitter and receiver modules developed in the project was built to transmit 112 Gb/s over 42 km standard single-mode fiber. Finally, we attempt an outlook on the prospective development of Ethernet standardization beyond 100GbE.

This chapter treats several approaches for employing nanophotonics or near-nanophotonics concepts to create low-power switches. The partly interrelated issues of low power dissipation and small device footprint are elucidated and figures of merit for switches formulated. Both optically and electronically controlled optical switches are treated and the crucial role of material development emphasized, illustrated by several examples, including both theoretical analysis of switch concepts and experimentally realized switches. Thus, electronically controlled switches based on hybrid, metamaterial and nanoparticle plasmonics, electrooptic polymers as well as switches based on silicon and photonic crystals are discussed. The all-optical switches focus on third-order nonlinear effects and carrier-induced refractive-index changes in III-V materials, as well as on emerging concepts of near-field-coupled quantum-dot switches. A brief comparison to electronic switches is done.